When my son, Casey was first diagnosed with autism at age four, I thought our world had ended. I thought our family was doomed to defeat and misery and decades of frustrated, circular searches for meaning: "Why us? Why him? Why anyone?" I can tell you with certainty that I have never been so wrong about anything in my life.

You see the thing with Casey is that he has this gift, which he shares with all those who take the time to know him, for finding delight in the most mundane situations. It is the flip side of autism; something the books and the specialists and the media scare-mongering never tell you.

Kids with autism, and their families, struggle with many challenges: difficulty with verbal and social communication and interaction; fine and gross motor difficulties; uneven developmental trajectories; crippling anxiety and self-regulation dysfunction. These cannot be minimized and the burden is not an easy one.

But kids with autism are also often singular in their attention to the things they love and the things that give them pleasure; this sometimes makes them wholly present and pure receptacles of joy.

For Casey, his love has always been city buses. This is not uncommon in a young child, but he loved them so much that before the age of three he had most of the city's bus routes memorized, and while he couldn't answer in full sentences (something that wouldn't come until after age six), his first words along with "mama" and "papa" were words like "articulated bus," "transfer" and "bus pass." We didn't know he had autism at the time; in retrospect, this should've been a clue.

By age five, while other kids were sounding out the words to their favourite Sesame Street books, Casey was sounding out, and quickly memorizing, all the words found on the free transit maps and bus schedules found around town.

It's often said that kids with autism don't have an imagination or, in the more nuanced books on the topic, lack "imaginary play." I've never found this to be the case with any of the kids I've seen on the spectrum. In fact, I'd argue the reverse from my parenting perspective. I think kids on the spectrum often have such vivid powers of imagination that the "real world" has difficulty competing.

In Casey's case, of course, he dreamt of city buses. He talked about them incessantly and when he conversed with others, the dialogue often went something like this (in rare full sentences): "Where do you live? Do you ride the bus? Which bus number do you take? Do you have a bus pass?" -- and so on. Once Casey exhausted this script, he'd ask the same questions to the same person all over again (and again), not because he'd forgotten or misunderstood the answers, but because he'd delight in them.

So it was with his imaginary play. Throughout our house, he created a vast labyrinth of bus stops replete with cut out paper bus numbers. But the most important bus stop of all was right in front of our house. He insisted that the city bus stops at the foot of our driveway and he created his own bus stop in his mind. Every day he'd play "buses" in front of his imaginary bus stop on our front yard.

Casey would tell friends and neighbours who would drop by about the bus stop at the end of our yard. They would look in earnest, but of course, there was nothing there to see, so they'd figure out he was playing, and gamely, play along. This went on for years.

That's why one Sunday morning when Casey pointed out our front window and said, "The bus is here!" with great enthusiasm, I said something like, "that's nice, honey" and didn't bother to look up. None of us did. So he said it again, "Look! The city bus!" "Uh huh," I responded two and three or more times. Until finally I looked up to appease him.

And there it was. At the end of our yard, sitting directly in front of Casey's imaginary bus stop was a real live bus. An articulated city bus to be exact.

Let me tell you how improbable this was. We live on a tiny dead-end street in a quiet little neighbourhood where no city bus would or could ever venture. There's nowhere for them to go, and there's almost no one for them to pick up.

So when I saw a city bus parked at Casey's imaginary bus stop I had to take a sip or two more of my morning caffeine before I could take it all in. But there it was. Like it had jumped from his head to his crayoned pages to life in our yard. I immediately thought this had to be planned. This had to be a crazy gift from one of our lovely neighbours who had endured Casey's imaginary bus scenarios at that very spot for years. I looked over at my husband to make sure he was not in some way responsible. But he looked as incredulous as I did.

Casey ran outside to watch his city bus, still parked in the imaginary bus stop -- now, not so imaginary. Then the neighbours started to come out too, to their front porches and decks and stoops, to see what the heck was going on.

Not only was there a real bus in Casey's imaginary bus stop, there were real people on the bus. They looked as confused peering out from their windows as we did peering in at them.

That's when we finally noticed the panicked bus driver. You see, our dead end street is compact enough that it was easy pulling in but getting out would be a whole other matter. It would take a skilled driver with nerves of steel to manage backing out an articulated bus with tight corners dodging parked cars, houses and curious onlookers.

So here's what really happened. It turns out it was a new bus driver who had to take a last minute detour from a major road nearby because of a charity marathon. She thought our street was a throughway back to the major arteries of the city, and now she was trapped.

For a full thirty minutes, Casey's real live bus sat at his imaginary bus stop. We all waited to see what would happen next. Finally, a senior bus driver arrived in another vehicle, took over, and with pretty impressive skills backed the articulated bus out in a single, long, fluid motion. The bus was back in business.

When it was finally gone, Casey grinned and turned to all of us and said: "I told you it was a bus stop." He went on playing as if nothing huge and improbable had just happened. His real bus gave him joy, but so had his imaginary buses. He was delighted by our participation in his bus game when the real bus came along. But the thrill for the buses was always there, real or not.

We were the ones who needed the real bus.

Casey's older brother turned to me and said, "Casey can make things come out of his head and happen." I had to admit it kind of felt that way that day.